Feed mechanism for woodworking machines



AMII.l JOHNSON.

FEED NIECHANISIVI FOR WOODWORKING MACHINES.

APPLICATION FILEU MAY 23. 192|.

PatentedSept. 5, 1922.

fla

Patented Sept. 5, 1922.

stares FEED MEGHANISM FOR: W'OODlWOT-'KNG- MACHINES.

Applicationfiled May 23, 19.21. Serial No. 471,881'.`

To all' fui/2,0m t may' concern Be it known that I, ALBERT Ai. JOHNSON,

a citizen of the United States, residing at Mount Holly, county. ofBurlington, and State of New Jersey, have invented anew and usefulImprovement in- Feed Mecha nisinA for lVoodworking Machines, of whichthe following is a full, clear, and exact dev-- scription, referencebeing had to the accompanying drawings, which form a part of thisspecication.

This inventionfrel'ates to an improvement in feed mechanism for feedingpieces of lumber *through a machine in which thepieces are operated onat different stations by different cutters, etc.

The precise nature of my invention wilrli be best understood by'reference to the accompanying drawings which will now be described, itbeing premised", however,- that various changes may be made in thedetails of construction without departing from the spirit and scope ofmy invention as defined' in the appended claims. y

Fig. 1 of the drawings isa longitudinal section through one form of myimproved feedingv mechanism which isv shown some-` whatdiagrammatical'ly for clearness.

Fig. 2 is a transverse sectional' view of a portionof the device showninFig. 1.v

Figs. and 4 are detail sectional views of the feed pins.

Fig. 5 is a fragmentary viewshowing a modification. f

In these drawings, the reference character 107 designates the frame of awood-working machine. Wood-working tools or cutters may be mounted onthe frame at all or any of the stations a, b, c and d, which tools maybe power driven in any desired manner, and from any desired source.

Mounted for reciprocation in suitable guides in the frame 10 of themachine are feed bars 11, there being one on each side of the machine.12 are spaced feed pins slidably mounted in the feed bars 11, and 13 areleaf springs connected to the bars 11, the free ends thereof engagingthe pins for positively moving the pins downwardly as hereinafterdescribed.

These pins are provided with rectangular body portions for presentingbroad surfaces to the lumber to be fed thereby as well as to providemeans for preventing the pins from rotating, and are also provided withprojecting circular stems which extend through circular openings in thebars`11.

14 are feed being one on1 each side of themachine, and are arranged tobe, moved. vertically in suit.- able guides on the `frame 10,' forraising the feed pins12i for lumber, such as'15, from station tostation, and to permitk said pins-.to drop below said pieces of' lumberwhen the feed bars 11 are.

returned as hereinafter set forth. 16 is a shaft jou'rn-aled in bearingson the frame 1f), and 17. are camssecu-red thereto, there being one oneach side of the machine. The shaft 16 may be driven in any desiredmanner to,y rota-te the cams 17 in the direc;- tien indicated bythearrow shown in.I F ig. 1. Connected te each cam 1T are roll'ersp18 onscrew pins adjustably mounted in radial slots therein, and which arearranged to engage projectionsv 19 on the feed bars 11 tof shift saidbars-to; feed the stri-ps of lumber from one position tothe next pastthe different stations. Eachffeed bar is provided with a returnr spring20, and a spring'- pressed stop! 21 'for limiting the returnmovement ofthe feed bar.` The stop is normally heldin its extended position by aspring 22 which .isstronger than spring 20, while the tension of thekspring 22l is arranged to be adjusted by a screw 28. g

24 kare levers pivoltally yconnected to brackets 25 adjnstably mountedon the frame 10. Each lever 24 is provided with a roller at one end forengagement with its cam 17 for rocking the leverto raise its. member-14through its connection therewith to raise the pins 12 to advance thestrips of lumber one step. 26 is a hold-down device for the strips 15which may be yieldingly held in any desired manner to hold the strips incontact with the rails or bed 27 of the machine.

In the operation of the device, the

strips to be fed through the machine are fed to the erstes;

JOHNSO1\TK,`OF MOUNT HOLLY, NEW' JERSEY.

pin elevating members, there,

advancing the pieces. off

fwy

bed between the first two pins 12 at the left hand end of the machine,and as the cams 17 are double cams each strip will be fed two steps foreach revolution of the shaft 16. As the cams 17 are rotated clockwisefrom the position shown, the peripheries of the cams will engage therollers on the ends of the levers 24, depress said ends of the levers,and elevate the bars 14 and raise the pins 12 into the plane of thestrips 15. One set of rollers 18 will then engage the projections 19 andadvance the strips one step, or from one station to the next. rTheprojections 1t should be so shaped as to cause the feed bars or lumbercarriers to move with a uniform speed throughout their travel.

The shape of the cams is such that the members 14 will again be in theirlowered positions before the feed bars 11 have been shifted to theireXtreme positions by the rollers 1S, but as the friction between thepins 12 and the strips 15 caused by the work required to shift thestrips between the holddown 26 and the bed is greater than the pressureof the springs 13 the pins 12 will not be lowered until the feedmovement of the bars 11 is completed. Immediately after the feedmovement ofthe bars 11 has been completed and the frictional resistanceto the downward movement of the pins has been removed, the springs 13will act to draw the pins 12 to their lowered positions before thesprings 2O act to return the feed bars to the position shown.

It is important that the two feed bars 11 should be operated at the sametime by` rollers 18. Projections 19 are therefore adjustably mounted onthe bars as shown in Figure 1.

Inlig. 5 is shown a modified form of mechanism for operating the feedbars. 1n place of cams 17, gears 170 are fixed to the driving shaft, onebeneath each of the feed bars. These gears are provided with teeth for aportion of their circumference only, which mesh with teeth on feed bars111. As the driving shaft is continuously driven, starting from theposition shown in Fig. 5, gears 170, only one of which is shown, willdraw the feed bars to the right as long as the teeth mesh. When theycome to the plane portions of their circumference, the feed bars will befreed and will be at once retracted by their springs 20. In this way anintermittent motion is given which feeds the barsv forward at a constantspeed. This method gives one reciprocation for each revolution of thedriving shaft, the length of motion being fixed by the length of thetooth portions of the gears.

Having now fully described my invention, what 1 claim and desire toprotect by Letters Patent is:

1. A feed mechanism for a work piece of the type described comprising afeed bar, means for reciprocating said bar, a pin in said bar, and meansfor reciprocating said pin in timed relation to the movement of the feedbar to shift the pin into feeding posi tion with relation to the workpiece on the forward movement of the bar and to retract the pin out ofthe line of movement of the work piece on the return movement of thebar.

2. A step by step feed mechanism for feeding strips from station tostation of a wood-working machine, having a feed bar on each side of themachine, cam means for reciprocating said bars, feed pins in each bar,cam means for raising said prins into the path of the strips to move thestrips forward, and spring means for retracting the pins out of thepathv of the strips after the strips have been shifted.

3. A step by step feed mechanism for feeding strips from station tostation of a wood-working machine, having a feed bar on each side of themachine, cam means for moving said bars, feed pins in each bar, cammeans for raising said pins, and springs for lowering said pins.

1. A step by step feed mechanism for feeding strips from station tostation of a woodworking machine, having a feed bar on each side of themachine, adjustable cam means for moving said bars, feed pins in eachbar, cam means for raising said pins, and springs for lowering saidpins.

in testimony of which invention, 1 have hereunto set my hand, at Phila.,Penna., on this 20th day of May, 1921.

ALBERT A. JOHNSON.

